Input voltage range is 100-240VAC at 50/60Hz with protection against over voltage, over current, and short circuits. Units have been tested and are in good working condition. eeTao offers a 30-day refund and 24 months of exchanges. The 3-prong 54.6V 2A AC/DC adapter charger is compatible with the iENYRID M4 Pro S / S+ Max electric scooter with a 48V 10Ah 16Ah lithium-ion battery. It comes with a 3-pin connector and is compatible with the FY1505462000 54.6V 2.0A switching power supply battery charger. Rechargeable batteries have a lifespan of 1 to 3 years, and a volt meter can be used to determine whether the battery or the charger is the issue.